Kaposi sarcoma of the musculoskeletal system: a review of 66 patients.

Kaposi sarcoma (KS) of bone and skeletal muscle is unusual. In this report, the authors review 66 published patients with KS who had involvement of the musculoskeletal system reported from 1925 to 2006. In only 3 patients was acquired immunodeficiency syndrome (AIDS)-related KS identified within skeletal muscle. Osseous KS lesions were more frequent and occurred with African, classic, and AIDS-related KS and occurred rarely in transplantation-associated KS. Patients seldom were asymptomatic. They usually had bone pain with limited mobility or infrequently developed serious sequelae like spinal cord compression. Locally aggressive African and classic KS lesions typically involved the peripheral skeleton; whereas, in patients with AIDS, the axial (vertebrae, ribs, sternum, and pelvis) and/or maxillofacial bones more commonly were involved. Almost all patients had concomitant nonosseous KS lesions. Joint involvement was exceptional, and pathologic fractures were not observed. Computed tomography scans and magnetic resonance images were better at detecting osseous KS lesions, which frequently went undetected on plain x-ray films or bone scans. Pathologic diagnosis was important to exclude similar lesions like bacillary angiomatosis. Treatment options, including surgery and, in more recent patients, radiation and/or chemotherapy, had limited success.